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Does a Dehumidifier Help With Allergies?

Updated on March 11, 2023
Written by
Danny Ashton
Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.

Can a dehumidifier be a solution to help those suffering with allergies?

Living with allergies can be a struggle as it is. What if those allergies are being triggered by something in your own home. Not cool.

If you’re starting to notice those subtle signs of suffering or have been affected by them in your home for a while now, there’s a chance it’s connected to either mold, mildew, dust mites, or all three.

There are a few different ways you can deal with allergies at home, and even though mold and dust mites are very different organisms, they share one strong trait: they both thrive in a humid environment. 

All hope is not lost, as an air dehumidifier can be the solution to your problems. But first let’s look at allergies, why they happen, what role humidity plays, and how you can prevent their effects in your household.

Is Humidity Bad for People With Allergies?

They say “The dose makes the poison” and that also applies to allergies. If humidity levels are above 50% in your home, then it can become harmful for people with allergies. If it’s in the 30-45% range, it’s less likely to trigger them. 

When humidity is higher than 50%, the mold, mildew, and dust mites start to grow and they can cause allergic reactions in people.

Mold, mildew, and dust mites all love humid environments. According to The National Center for Biotechnology Information research, mite populations are minimized when the relative humidity is below 50% and reach a maximum size at 80% relative humidity.

Mites trigger allergic reactions and if they thrive in an environment, they can cause multiple symptoms such as: 

  • difficulty breathing
  • running nose
  • trouble sleeping
  • cough
  • postnasal drip

On the other hand, mold is a type of fungus that is found almost everywhere. The problem is when particles of mold land in the interior of your house, on a humid surface, and start to reproduce. When it grows, mold tends to release spores in the air that people can easily inhale. 

Mold can cause allergic reactions and impair breathing, causing shortness of breath, dry skin, skin rash, etc.

If the humidity levels are more than 50%, you should invest in an air dehumidifier. According to research, a dehumidifier paired up with air conditioning that keeps the room at less than 50% humidity is ten times more potent in preventing allergies than opening windows or just using air conditioning. 

So it pays to use dehumidifiers to prevent fungus, mold, mildew, and dust mites from becoming prevalent in your household and causing allergic reactions. 

But don’t overdo it with a dehumidifier. During cold, winter months the humidity levels can drop to less than 30% which can cause problems for people with asthmatic problems. During those months and if you have problems with respiratory diseases, you should have an air humidifier that would put your room’s humidity between 30-45%. 

According to the Journal of Allergy and Clinical Immunology study, bronchoconstriction and exercise-induced asthma (EIA) were distinctly more pronounced in the dry than in the humid climate. So try to keep the room’s humidity level in the Goldilocks range— 30 to 45%. 

Can a Dehumidifier Help With Allergies?

If you’re not sure of the differences between a dehumidifier vs an air purifier, we got you covered.

An air dehumidifier extracts excess moisture from the air and condenses it into small drops that drip into its water collection bucket. That process lowers the humidity levels in your home and with lower levels, mold, mildew, and dust mites don’t have the necessary “fuel” to keep growing so they diminish drastically and don’t cause harm to people with allergies.

Not only will you prevent the growth of allergens in your house, but you will also limit the symptoms of allergies you can have. During spring (pollen) season, you can use air conditioning and purifiers to remove the pollen that causes allergic reactions from your rooms. 

And by not breathing in the damaging spores of mold and mildew, you will limit their impact on your health. 

There are a couple of more ways you can help out your dehumidifier to solve the problem with allergies in your house. 

What else can help relieve allergies in the home?

There are a couple of things you can do in your home that would help remove allergies.

These tips work in almost all climates and for nearly every room in the house, whether it’s the basement, bathroom, living room, kitchen, or bedroom. 

  • Use plastic to store stuff. When you use plastic, the mold and dust won’t get inside the plastic containers/boxes. Keep children’s toys, books, and magazines in these containers and seal the lids on them.
  • Use an air filter. An air filtration system can help remove allergens from the room. Air purifiers with HEPA filters trap allergens and particles such as pollen, dust mites, and odors. We recently published a guide to what we think is the best air purifier for allergies based on HEPA filter performance for pollen and those that are easy to live with.
  • Vacuum carpets whenever you can. Carpets tend to hold things in them so it’s better to vacuum them as often as possible.
  • Wash your bedding often. You should wash your bedding quite often and do it at higher temperatures. Dust mites love beddings since they grow in humid environments and can eat the remaining shedding of your skin (yes, you shed skin cells and there are small bugs that like that).

No pets in the house. Pets like cats and dogs tend to shed dander all around the house which is a big no-no when it comes to allergies. Try to keep the pets out of the house, but if you can’t, at least keep them out of the bedroom.


As we have seen, humidity is quite a large trigger for people who have allergies. That’s because mold, mildew, and dust mites— the organisms that can cause allergies—all thrive in highly humid environments. 

An air dehumidifier can greatly help with that, lowering the relative humidity of the room and household to less than 50%, where the above-mentioned organisms can’t thrive.    

So if you’re having problems with allergies and haven’t invested in an air dehumidifier, you should definitely invest in getting one for your household. 


Indirect health effects of relative humidity in indoor environments (1986). NCBI.gov. ncbi.gov

Reducing relative humidity is a practical way to control dust mites and their allergens in homes in temperate climates (2001). PubMed. pubmed.gov

Effects of dry and humid climates on exercise-induced asthma in children and preadolescents (1977). JaciOnline. Jacionline.org

About the author

Danny Ashton

Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.